Footage from Associated Press Television News in Pyongyang showed Ms. Amos stepping off a shuttle bus and being greeted at the airport.

Ms. Amos is to meet with North Korean officials and take a field trip to look at conditions outside Pyongyang during her five-day trip. She is to visit hospitals, an orphanage, farms and a food distribution center.

She said she is “particularly concerned” over reports about worsening malnutrition among North Korean children.

The United Nations launched an appeal in April after a survey concluded that some 6 million people needed emergency food aid because of floods and a harsh winter.